The present invention relates to a frame and suspension assembly for motor vehicles. More specifically, the invention relates to a frame and suspension assembly having stabilizing means associated therewith wherein the assembly, when incorporated in a vehicle presents a low frame rail height above ground. The assembly of the present invention includes an air spring suspension system mounted outwardly of the frame rails to thereby provide the aforementioned low frame rail height and to provide improved stabilization for a motorized vehicle. A reinforced notch in each of the frame rails of the assembly maintains adequate clearance for the rear axle of the vehicle and an anti-sway bar is positioned to prevent excessive swaying of the frame.
Frame assemblies for motor vehicles such as light trucks are known in the prior art which have incorporated various means for stabilizing the vehicle to prevent excessive bounce and sway and the like during operation. Such frame assemblies have included air spring suspension systems and anti-sway bars. The air springs suspension systems generally include a walking beam or trailing arm pivotally mounted to a mounting bracket and extending rearwardly to an air spring mounted between the walking beam and the bottom of the frame rail so that the entire frame rail is positioned on top of the air spring. Anti-sway bars are often mounted to the differential housing and to one of the frame rails of the assembly.
Although the prior assemblies incorporating air spring suspension systems and anti-sway bars have provided a measure of stabilization for vehicles incorporating those assemblies, they heretofore could not be incorporated in a vehicle to provide a low frame rail height so that light duty trucks, such as delivery trucks and the like can be constructed with lower load carrying surfaces or compartments which can be loaded and unloaded with less effort than is required with more conventional truck designs. Previous assemblies which utilize an air spring suspension system have failed to provide a high degree of frame stability while also providing the aforementioned low frame rail height. This is because it has been difficult in such assemblies to simultaneously lower the frame rail height while maintaining adequate structural clearance for the rear axle and at the same time providing a high degree of on-road stability which is at least comparable or better than has been previously possible.
The present invention overcomes the shortcomings of the prior art by providing a frame and suspension assembly for motor vehicles such as delivery and other light duty trucks where it is desirable to have a low chassis frame height. The assembly of the invention includes a pair of frame rails having reinforced notches over the rear axle housing. An air spring suspension system is mounted outwardly of the frame rails along a pivotally mounted walking beam which extends from a mounting bracket rearwardly along the frame rail to an air spring mounted between upper and lower mounting plates. The air spring mounting plates extend outwardly from the frame for positioning of the air springs therebetween in a manner which allows each frame rail to be lower to the ground than was previously possible. The rear axle extends transversely underneath the parallel frame rails and is affixed at its ends to the walking beams. A reinforced notch is provided in each of the frame rails to provide structural clearance for the rear axle to maintain the frame rails in their low-to-the-ground position, as is further discussed and described herein
Positioning of an air spring suspension system outwardly of the frame rails provides, in addition to a lower chassis frame height, improved suspension and overall stability. An anti-sway bar is preferably mounted behind the rear axle and positioned between a frame rail and the opposing walking beam which also stabilizes the assembly. The frame and suspension assembly is preferably constructed to prevent the rear axle and the differential from rising above the tops of the frame rails even when the frame and suspension assembly is subject to heavy loads. Accordingly, the body of the motor vehicle incorporating the frame assembly to the present invention does not have to be raised to accommodate the differential or axle housing thereby allowing a vehicle manufacturer to maintain the load carrying portion of the vehicle in a low-to-the-ground position for easy access thereto.
It is accordingly an object of the present invention to provide a frame and suspension assembly for a motorized vehicle.
It is another object of the present invention to provide a frame and suspension assembly having a low frame rail height when incorporated in a motor vehicle.
These and other objects and advantages of the present invention will be readily understood by those skilled in the art upon further consideration of the remainder of the disclosure.